<template>
  <div class="score-case">
    <div class="table">
      <table>
        <thead>
          <tr>
            <th>编号</th>
            <th>科目</th>
            <th>成绩</th>
            <th>考试时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <tbody>
          <tr v-for="(item,index) in list" :key="item.id">
            <td>{{ index + 1}}</td>
            <td>{{ item.subject }}</td>
            <!-- 渲染样式动态v-bind,省略  ：class -->
            <!-- 小于60分的变红 其他为空 三元表达式-->
            <td :class="item.score < 60 ? 'red' : '' ">
              {{ item.score }}</td>
            <td>{{ formatDate(item.date) }}</td>
            <!-- 时间 -->
            <!-- 给删除绑定点击事件，删除是根据ID进行删除的所以要传参item.id -->
            <td><a href="#" @click.prevent="delFn(item.id)">删除</a></td>
          </tr>
        </tbody>
        <tbody v-show="list.length === 0">
          <tr>
            <td colspan="5">
              <span class="none">暂无数据</span>
            </td>
          </tr>
        </tbody>
        <tfoot v-show="list.length > 0">
          <tr>
            <td colspan="5">
              <span>总分：{{ sumScore }}</span>
              <span style="margin-left:50px">平均分：{{ avgScore }}</span>
            </td>
          </tr>
        </tfoot>
      </table>
    </div>
    <div class="form">
      <div class="form-item">
        <div class="label">科目：</div>
        <div class="input">
          <input v-model.trim="subject" type="text" placeholder="请输入科目" />
        </div>
      </div>
      <div class="form-item">
        <div class="label">分数：</div>
        <div class="input">
          <!-- 双向绑定属性 v-model="变量"  此处是数字，要进行数字转换 -->
          <input v-model.number="score" type="text" placeholder="请输入分数" />
        </div>
      </div>
      <div class="form-item">
        <div class="label"></div>
        <div class="input">
          <!-- 给添加保存绑定点击事件 -->
          <button class="submit" @click="btnFn">添加</button>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import moment from 'moment'
export default {
  
  name: 'ScoreCase',
  data () {
    return {
      list: JSON.parse(localStorage.getItem('score-case')) || [],
      subject: "",
      score: ""
    }
  },
  computed:{
    sumScore(){
      return  this.list.reduce((sum,item) => sum + item.score,0)
    },
    avgScore() { c
      return this.list.length
        ? (this.sumScore / this.list.length).toFixed(2)
        : 0;
    },
  },

  
  //三种方法：两个点击事件，一个时间
  methods:{
    // 添加点击保存事件
    btnFn(){
    //对输入内容进行判断，超出范围进行提醒
    if(this.score >= 0 && this.score <= 100 && this.subject){
      //满足分数和科目填写的条件，进行提交    
      this.list.push({
         id: this.list.length ? this.list.length + 1 : 0,
        // id:this.list.at(-1).id + 1,
        subject: this.subject,
        score: this.score,
        date: new Date()
      })
      // 输入框进行清空
      this.subject = "",
      this.score = ""
    }else{
      //不满足条件
      alert('请输入正确的格式')
    }
    },
    //  点击删除事件
    delFn(id){
      // console.log(id);//根据id找索引
      //   const index = this.list.findIndex(item => item.id ===id)
      //   this.list.splice(index,1)
      // filter  id不同的留下，相同的删除 根据id删除元素
      this.list = this.list.filter((item) => item.id !== id)
    },
    formatDate(dt){
      // 返回时间
      return moment(dt).format("YYYY-MM-DD HH-mm-ss")
    },

  },
  // 事件监听
  watch:{
    list:{
      deep:true,//深度监听
      handler(){
        localStorage.setItem('score-case',JSON.stringify(this.list))
      }
    }
  }
};
</script>

<style lang="less">
.score-case {
  width: 1000px;
  margin: 50px auto;
  display: flex;
  .table {
    flex: 4;
    table {
      width: 100%;
      border-spacing: 0;
      border-top: 1px solid #ccc;
      border-left: 1px solid #ccc;
      th {
        background: #f5f5f5;
      }
      tr:hover td {
        background: #f5f5f5;
      }
      td,
      th {
        border-bottom: 1px solid #ccc;
        border-right: 1px solid #ccc;
        text-align: center;
        padding: 10px;
        &.red {
          color: red;
        }
      }
    }
    .none {
      height: 100px;
      line-height: 100px;
      color: #999;
    }
  }
  .form {
    flex: 1;
    padding: 20px;
    .form-item {
      display: flex;
      margin-bottom: 20px;
      align-items: center;
    }
    .form-item .label {
      width: 60px;
      text-align: right;
      font-size: 14px;
    }
    .form-item .input {
      flex: 1;
    }
    .form-item input,
    .form-item select {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      width: 200px;
      height: 40px;
      box-sizing: border-box;
      padding: 10px;
      color: #666;
    }
    .form-item input::placeholder {
      color: #666;
    }
    .form-item .cancel,
    .form-item .submit {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      border-radius: 4px;
      padding: 4px 10px;
      margin-right: 10px;
      font-size: 12px;
      background: #ccc;
    }
    .form-item .submit {
      border-color: #069;
      background: #069;
      color: #fff;
    }
  }
}
</style>